Sajad H Wani

Tectorigenin ablates the inflammation-induced epithelial–mesenchymal transition in a co-culture model of human lung carcinoma

OBJECTIVES Tumors not only manage to escape from the host immune system, but they effectively contrive to benefit from infiltrating immune cells by modifying their functions so as to create a pro-inflammatory microenvironment favorable for tumor progression and metastasis. In this study we investigated if tectorigenin could suppress lung cancer-induced pro-inflammatory response generated from monocytes. MATERIALS AND METHODS A549:THP1 co-culture model was set-up favoring release of pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α). Effect of tectorigenin on A549 imparted invasive phenotype of A549:THP-1 co-culture was monitored by cytokine release from monocytes, and metastasis/epithelial-mesenchymal transitiom (EMT) in A549 cells. RESULTS In a contact A549:THP1 co-culture model, THP-1 cells were activated by A549 cells favoring secretion of pro-inflammatory cytokines, TNF-α and IL-6. However, priming of A549 cells with tectorigenin for 24h repressed A549 cell-induced secretion of TNF-α and IL-6 by THP-1 cells. Tectorigenin induced change in functional phenotype of A549 cells rendered THP-1 cells non-responsive for the secretion of IL-6 and TNF-α in a contact co-culture setup. Additionally, conditioned media from this non-responsive A549:THP-1 co-culture suppressed metastatic potential of A549 cells as confirmed by the wound healing and transwell migration assays. These finding were further corroborated by decrease in expression of Snail with a concomitant increase in E-cadherin, the two signature markers of EMT. CONCLUSION These results clearly demonstrate the therapeutic potential of tectorigenin to prevent lung cancer elicited inflammatory and pro-metastatic response in monocytes and warrants further investigations to elucidate its mechanism of action.

Relative expression of apocarotenoid biosynthetic genes in developing stigmas of Crocus sativus L.

Saffron, the desiccated stigmas of Crocus sativus, is recognized for its attractive color, flavor, and aroma which are due to the accumulation of crocin, picrocrocin, and safranal, respectively. HPLC analysis demonstrated maximum apocarotenoid accumulation during the fully developed scarlet stage of stigma development followed by the orange and yellow stages of stigma development. Reverse Transcription-PCR analysis revealed a concurrent expression pattern of CsZCD and CsLYC genes in a developmental stagespecific manner. However, CsBCH and CsGT2 genes were specifically expressed during the mature, scarlet stage of stigma development. Real-Time PCR analysis showed a sharp increase in gene expression of CsLYC gene during stigma development indicative of its possible regulatory role in apocarotenoid biosynthesis or stigma development. Results suggest that genetic manipulation of this gene can help to improve the quality of stigma in saffron; besides highlighting its potential to monitor stigma development during in vitro experimentation.

A novel kinase mutation in VEGFR-1 predisposes its αC-helix/activation loop towards allosteric activation: Atomic insights from protein simulation.

Vascular endothelial growth factor receptor 1 (VEGFR-1) has been implicated in diverse pathologies, including cancers. Although VEGFR-1 is considered as functionally impaired kinase, its decoy characteristics make it an important regulator of VEGFR-mediated signaling, particularly in tumor angiogenesis. VEGFR-1 conveys signaling via its tyrosine kinase (TK) domain whose activation is regulated by phosphorylation of specific tyrosine residues. Thus dysregulation of VEGFR-1 signaling, as reported in most of the cancers, might be a consequence of altered phosphorylation that could be attributed to genotypic variations in its TK domain. Considering the importance of TK domain of VEGFR-1, we carried out its mutational screening in 84 clinically validated and histopathologically confirmed colorectal cancer patients. By means of direct DNA sequencing and SNP analyses, eight novel variations, including one synonymous, two deletion, one missense and four intronic variations, were reported in the TK domain of VEGFR-1. rs730882263:C>G variation specifically reported in colon cancer, representing a single-atomic change (Sulfur to Oxygen) in the predicted (p.Cys1110Ser) protein, was observed as potentially deleterious variation as assessed by multiple single-nucleotide polymorphism prediction servers. Molecular dynamics simulations of VEGFR-1 Wt and (p.Cys1110Ser) variant models revealed major conformational changes in variant protein presumptuously generating an open conformation thereby exposing the activation domain and consequently increasing the probability of phosphorylation events: a condition frequently reported in cancers.